<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<input type="checkbox" checked="checked" />
		<input type="checkbox" checked="true" />
		<input type="checkbox" checked="false" />
		<input type="checkbox" checked="" />
		<input type="checkbox" checked="null" />
		<input type="checkbox" checked="undefined" />
		<input type="checkbox" checked=0 />
		<input type="checkbox" checked />
		<input type="checkbox" checked="随便写都能选中" />
		<!-- 只有选不中 -->
		<input type="checkbox" />
	</body>
</html>
